The present invention relates to a specular system for recovering the energy of a laser beam, more particularly a laser beam utilized to heat a workpiece.
It is well-known that laser beam energy may be used to heat workpieces either as a heat treat for the workpiece or to raise its temperature prior to subsequent machining operations. This is accomplished by directing the laser beam onto a point on the surface of the workpiece. The laser beam is typically directed onto the workpiece at an angle and a portion of the energy of the laser beam is reflected by the surface of the workpiece. The proportion of the reflected energy, which may be as high as 80% to 90% of the laser beam, is wasted energy. Accordingly, there is a substantial waste of energy and precautions must be taken to avoid damage which may be caused by the reflected laser beam.
The heat absorption by the workpiece from the laser beam may be increased, under ideal conditions, by adjusting the incidence angle of the beam and the light polarization direction. However, the ideal conditions required by these parameters are very often difficult to ascertain and are difficult to carry out under actual operating conditions. As a practical matter, there is little chance of actually improving the efficiency with this approach.